WASHINGTON 
GOP lawmakers have subpoenaed the private emails of Labor secretary-nominee Thomas Perez, a possible sticking point ahead of his Senate confirmation hearing next week.

The subpoena, issued Wednesday by House Oversight Committee Chairman Darrel Issa, R-Calif., to the Justice Department, seeks the emails as part of an investigation into an agreement Perez brokered last year in his capacity as the nation's top civil rights enforcer.

In the deal, Perez persuaded the city of St. Paul, Minn., to withdraw a lending discrimination lawsuit before it could be heard by the Supreme Court. In exchange, the Justice Department declined to join two whistleblower lawsuits against the city that could have returned millions of dollars in damages to the federal government.

Republicans have criticized the deal, which Justice Department officials say they reached out of concern the court might strike down their use of statistics in housing discrimination cases.

Perez has already turned over hundreds of official emails and documents to lawmakers who have been investigating the arrangement. But investigators say they also obtained from a third party an email that Perez sent from his personal Verizon account to the attorney for St. Paul. That email set a date for a meeting.

House Republicans led by Issa and Virginia Rep. Robert Goodlatte, chairman of the House Judiciary Committee, say they are troubled that Perez used personal email to conduct official business and didn't turn it over to investigators.

On March 27 and again on April 4, the lawmakers, joined by Iowa Sen. Charles Grassley, top Republican on the Senate Judiciary Committee, requested all of Perez's personal emails that relate to official business.

"Your use of a non-official email account to conduct official government business frustrates the goals of transparency laws, such as the Federal Records Act and the Freedom of Information Act," the April 4 letter said.

On Tuesday, Justice sent Issa one additional personal email on the St. Paul matter that had not been previously disclosed. That didn't satisfy Issa, who is now seeking to subpoena all personal emails used for Justice Department business.

The subpoena was first reported by the Wall Street Journal.

In a March 22 interview with congressional investigators, Perez was asked whether he had ever conducted official business from his personal email account. Perez said: "I don't have any recollection of having communicated via personal email on this matter."

Spokeswoman Dena Iverson said Thursday that the Justice Department is reviewing the committee's subpoena.

"The department has already devoted significant time and resources in order to cooperate with the committees' requests, including providing them with over 1,400 pages of documents as well as dozens of hours of interviews with multiple department officials," Iverson said.

Iverson said Perez's resolution of the cases was "in the best interests of the United States and consistent with the department's broad discretion to consider policy and other factors - including pending litigation - in resolving False Claims Act matters."

She said Perez consulted with career ethics officers at the Justice Department before making the deal.